Extremely active and nervous, they have a higher metabolic rate than any other animal. The heart of the masked shrew, Sorex cinereus, beats 800 times a minute, considerably faster than that of the hummingbird. Shrews must eat incessantly in order to stay alive; most will starve to death if deprived of food for half a day. They eat anything available, but prefer small animals; they are economically important as destroyers of insects and slugs that harm crops.Read more: http://www.answers.com/topic/shrew#ixzz2V0VbDFJE

Shrews are easily startled and will jump, faint, or drop dead at a sudden noise. They are vicious fighters, killing and eating larger animals, such as mice, as well as other shrews. A belief that the shrew’s bite is poisonous was dismissed for years as a folk tale, but has since been substantiated; the saliva of at least one species of shrew is lethal to mice and can cause considerable pain to humans. Shrews live about 15 months and reproduce rapidly, bearing up to four litters a year, with up to eight young in a litter.Read more: http://www.answers.com/topic/shrew#ixzz2V0VvnGXT

Shrews are solitary individuals that establish distinct territories. Couples are found together only during mating. The female builds the nest, a hole in the ground lined with leaves and moss, where she deposits her litter of 5-10 young, born after a gestation period of between 2-3 weeks. The female mates at the age of 1 year; however, since the life-span of the shrew is only 15 months, the females always die during the fall after the litter is bomRead more: http://www.answers.com/topic/shrew#ixzz2V0WC9l4z